Denki Kagaku Kogyo Kabushiki Kaisha

Yasuhisa Nishi

Mitsuyoshi Iwasa

Syuji Sasaki

Takashi Fukuda

Shuji Sasaki

Hiroshi Murata

Hidetoshi Naito

Keishi Iizuka

Tohru Umezaki

Shinji Yamano

A semiconductor encapsulation material which exhibits a low viscosity and further improved moldability in encapsulation even when highly loaded with an inorganic filler; an amorphous siliceous powder suitable for the preparation of a resin composition useful as the encapsulation material; and a process for the production of the amorphous siliceous powder. An amorphous siliceous powder having a content of Si and Al of 99.5 mass % or above in terms of oxides, wherein the Al content in the particle size region of 15 &#x3bc;m to less than 70 &#x3bc;m is 100 to 30000 ppm in terms of oxides; the Al content in the particle size region of 3 &#x3bc;m to less than 15 &#x3bc;m is 100 to 7000 ppm in terms of oxides; and the Al content in the whole particle size region is 100 to 25000 ppm in terms of oxides. It is preferable that the (A)/(B) ratio of the Al content (A) in the particle size region of 15 &#x3bc;m to less than 70 &#x3bc;m to the Al content (B) in the particle size region of 3 &#x3bc;m to less than 15 &#x3bc;m be 1.0 to 20.

Amorphous siliceous powder, process for production thereof, resin composition, and semiconductor encapsulation material

A silica powder containing an ultrafine powder in an amount of from 0.1 to 20 mass % and having an average sphericity of at least 0.85, wherein the ultrafine powder has, as the particle size measured by a dynamic light scattering particle size distribution measuring apparatus, an average particle size of from 150 to 250 nm, less than 10 mass % of the ultrafine powder having a particle size of at most 100 nm being less than 10 mass % (not including 0 mass %) and from 10 to 50 mass % of the ultrafine powder having a particle size exceeding 100 nm and not exceeding 150 nm.

Silica powder, process for its production, and composition employing it

The present invention provides ceramic powder capable of being incorporated into rubber or a resin for the preparation of a composition, which shows excellent heat resistance and flame retardancy and which is used, for instance, as a semiconductor-sealing material. The ceramic powder has a multi-peak frequency distribution pattern having at least two peaks as a particle size distribution as determined using a laser diffraction-scattering type particle size-analyzer, wherein the maximum particle size for the first peak ranges from 40 to 80 &#x3bc;m and that for the second peak ranges from 3 to 8 &#x3bc;m and wherein the rate of the particles having a particle size of not less than 20 &#x3bc;m and less than 40 &#x3bc;m is not more than 20% by mass (inclusive of 0% by mass).

Ceramic powder and applications thereof

The present invention herein provides ceramic powder which is to be incorporated into rubber or a resin and which can be used as, for instance, a semiconductor-sealing material and for the preparation of a composition excellent in the narrow interstice-filling up property and moldability. The ceramic powder has a multiple peak-frequency type particle size distribution which has at least two peaks, as determined according to the laser diffraction-scattering type particle size distribution analyzer, wherein the maximum particle size observed for the first peak falls within the range of from 12 to 30 &#x3bc;m; that observed for the second peak falls within the range of from 2 to 7 &#x3bc;m; the content of the particles having a particle size of greater than 7 &#x3bc;m and less than 12 &#x3bc;m is not more than 18% (including 0%); and wherein the ratio (F2/F1) of the frequency value F2 of the maximum particle size for the second peak to that F1 of the maximum particle size for the first peak ranges from 0.5 to 1.3.

Ceramic powder and use thereof

To provide an amorphous silica powder suitable for a sealing material for semiconductors having improved HTSL properties and HTOL properties, and a process for its production. An amorphous silica powder containing Al in an amount of from 0.03 to 20 mass % as calculated as AlOmeasured by atomic absorption spectrophotometry, wherein the average particle size is at most 50 &#x3bc;m, and when the amorphous silica powder is divided according to the average particle size into two powders, a powder having a particle size smaller than the average particle size has a higher content as calculated as AlOthan a powder having a particle size larger than the average particle size.

Amorphous silica powder, process for its production, and sealing material for semiconductors

The present invention herein provides fine inorganic hollow powder having a high hollowness rate, which can be incorporated into, for instance, a low dielectric rubber or resin composition. The inorganic hollow powder has an average hollowness rate of higher than 70% by volume and an average particle size ranging from 3 to 20 &#x3bc;m and the powder preferably has an average hollowness rate ranging from 75 to 85% by volume, an average particle size ranging from 5 to 15 &#x3bc;m, a maximum particle size of not more than 25 &#x3bc;m, a specific surface area of not more than 10 m/g, an average sphericity degree of not less than 0.90 and a purity of not less than 99% by mass. The inorganic hollow powder can be prepared by a method comprising the steps of forming a flame using a burner provided with at least a triplet-tubular portion comprising, in order from the outermost side, a combustion-improving gas-supply pipe, a combustible gas-supply pipe and an inorganic raw powder-supply pipe assembled together; injecting, into the flame at a high discharge speed, inorganic raw powder having a specific particle size through the inorganic raw powder-supply pipe, while the powder is entrained with a carrier gas having a specific relative humidity, to thus subject the powder to a heat-treatment.

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Omuta, Japan

Yasuhisa Nishi